Brush-holder for commutators



(No Model.)

I. H. BARTHOLOMEW.

BRUSH HOLDER FOR OOMMUTATORS. No. 452,561. Patented May 19,1891.

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UNITED STATES PATENT OFFICE.

ISAAC II. BARTHOLOMEIV, OF NORTII'FORD, CONNECTICUT.

BRUSH-HOLDER FOR COMMUTATORS.

SPECIFICATION forming part of Letters Patent N 0. 452,561, dated May 19,1891.

Application filed January 19, 1891. Serial No. 378,234. (No model.)

To all whom it may concern:

Be it known that I, ISAAC H. BAR'IHOLO- MEW, of Northford, in the countyof New Haven and State of Connecticut, have invented a new Improvementin Brush-Holders for Commutators for Dynamo Electric Machines; and I dohereby declare the following, when taken in connection with accompanyingdrawings and the letters of reference marked thereon, to be a full,clear, and exactdescription of the same, and which said drawingsconstitute part of this specification, and represent, in-

Figure 1 aview in vertical longitudinal section of a brush-holderconstructed in accordance with my invention, the commutator beingindicated by broken lines; Fig. 2, a view thereof in front elevationwith the brush removed 5 Fig. 3, a view of the device in verticaltransverse section 011 line a b of Fig. 1; Fig. 4, a plan view of myimproved device.

My invention relates to an improvement in holders for commutator-brushesfor dynamoeleetric machines, the objectbeing to produce a simple,compact, convenient, and effective device adapted to be operated withoutthe removal of any of its parts or the use of tools.

IVith these ends in view my invention 0011- sists in the combination,with a springactuated brush-carrier loosely mounted upon a horizontalshaft, of a bearing-piece frictionally mounted upon the said shaft andforming a stop for the carrier, and a stop rigidly secured to the shaftand arranged to limit the forward rotation of the bearing-piecethereupon.

My invention further consists in certain details of construction andcombinations of parts, as will be hereinafter described, and pointed outin the claims.

As herein shown, the brush-carrier is composed of abox or body A, havinga long narrow slot B formed in it to receive the brush C, and providedwith a thumb-screw D, which is screwed down upon the brush to hold thesame in place in the box or body, which is also composed of two paralleldepending lugs E E, separated by the width of the bearingpiece F, whichis located between them, and each provided with an opening G to receivethe shaft H, upon which the brush-carrier is thus mounted so as to movefreely. The said box or body is also provided at its rear and forwardends with ears I I, located in line with each other and on the samelevel with the bottom of the slot B which receives the brush. These earsI are best shown in Fig. 4 of the drawings.

The bearing-piece F, which is best shown in Fig. 1 of the drawings, issplit on the line F, forming two lugs F F, which are furnished withaligned and threaded perforations to receive a set-screw F by means ofwhich the said lugs are drawn together and the bearing-piecefrict-ionally clamped upon the shaft H before mentioned. The rear end ofthe bearing-piece has its upper face beveled, as at K, whereby clearancefor the rocking action of the brush-carrier is provided, and is extendedbeyond the said bevel to form the handle J, by means of which thebearingpiece is turned upon the shaft against the friction under whichit is clamped thereon. A flat spring L, pivoted to the upper face of theforward end of the bearing-piece, ext-ends throughout the length thereofand engages at its rear end with the under face and rear ear, I of thebrush-carrier and exerts a constant effort to throw the same forward,whereby the brush C is pressed against the commutator, so that a goodcontact therewith is maintained and the wearing away of the brushcompensated for.

In order to disengage the brush from the commutator, the handle J isborne down upon and the bearing-piece rotated on the shaft 11, uponwhich it is frictionally clamped, as has been described, this frictionbetween the shaft and bearing-piece being sufficient to hold the latterin any desired position. In order, however, to prevent it from beingthrown to far forward in restoring the brush to engagement with thecommutator, a stop rigidly secured to the shaft is provided. Thisconsists, as herein shown, of a small collar M, rigidly secured to theshaft by a set-screw M and provided with a projecting finger M carryinga pin M, the latter being arranged to extend parallel with the shaft andto stand directly under the forward end of the bearing-piece, the collarM being adjusted upon the shaft so that the said end of the bearing- Toopiece will engage with the pin when the bearingpiece has been rotated tothe limit of its rotation toward the commutator. The brushcarrier,bearing-piece, and stop are thus independently movable on the shaft.

The range of rocking movement given to the brush-carrier by beveling therear end of the bearing-piece is sufficient to enable the device to beset so as to compensate for the wearing away of the brush foraconsiderable time. Then when the brush is worn away so that the forwardear of the brush-carrier engages with the forward end of thebearingpiece the thumb-screw D is loosened and the brush slippedlengthwise in its slot 13 until it has tipped the brush-carrier back tothe limit of its rearward movement with respect to the bearing-piece.

My improved device is very compact and convenient and reduces the careof the commutator-brush to the minimum.

I would have it understood that I do notlimit myself to the exactconstruction shown and described, but hold myself at liberty to makesuch changes and alterations as fairly fall within the spirit and scopeof my invention. I am aware, however, that it is old to make a rockingbrush-carrier and employ a spring interposed between it and abearingpiece mounted on the same shaft for throwing it toward thecommutator-wheel, and I do not therefore claim such a constructionbroadly.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1, In a holder for commutator-brushes, the combination, with a shaft, ofa brush-carrier having two depending perforated lugs by which it isloosely mounted on the said shaft, a bearing-piece frictionally mountedon the said shaft and located between the lugs of the brush-carrier, aspring arranged to exert a constant effort to throw the brush-carrierforward toward the commutator, and a stop mounted upon the shaft andarranged to limit the forward rotation of the bearing-piece thereupon,the said brush-carrier, bearingpiece, and stop being independentlymovable on the shaft, substantially as set forth.

2. In a holder for commutator-brushes, the combination, with a shaft, ofa brush-carrier having two depending perforated lugs by means of whichit is loosely mounted on the shaft, a bearing-piece having twoperforated lugs by means of which it is friotionally mounted on the saidshaft located between the lugs of the brush-carrier having the rear endof its upper face beveled and provided with a rearwardlyextendinghandle, a flat sheet-metal spring located horizontally between thebrush-carrier and bearing-piece and arranged to exert a constant effortto rotate the brush-carrier toward the commutator, and a stop mountedupon the shaft and arranged to limit the forward rotation of the saidbearing-piece thereupon, the brush-earrier, bearing-piece, and the stopbeing independently movable on the shaft, substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

ISAAC II. BARTIIOLOMEW.

Witnesses:

G. A. SMITH, C. E. SMITH.

